Medial meniscal ramp lesions in ACL-injured elite athletes are strongly associated with medial collateral ligament injuries and medial tibial bone bruising on MRI

Purpose Medial menisco-capsular separations (ramp lesions) are typically found in association with anterior cruciate ligament (ACL) deficiency. They are frequently missed preoperatively due to low MRI sensitivity. The purpose of this article was to describe demographic and anatomical risk factors for ramp lesions, and to identify concomitant lesions and define their characteristics to improve diagnosis of ramp lesions on MRI. Methods Patients who underwent anterior cruciate ligament (ACL) reconstruction between September 2015 and April 2019 were included in this study. The presence/absence of ramp lesions was recorded in preoperative MRIs and at surgery. Patients’ characteristics and clinical findings, concomitant injuries on MRI and the posterior tibial slope were evaluated. Results One hundred patients (80 male, 20 female) with a mean age of 22.3 ± 4.9 years met the inclusion criteria. The incidence of ramp lesions diagnosed at surgery was 16%. Ramp lesions were strongly associated with injuries to the deep MCL (dMCL, p < 0.01), the superficial medial collateral ligament (sMCL, p < 0.01), and a small medial–lateral tibial slope asymmetry (p < 0.05). There was also good correlation between ramp lesions and bone oedema in the posterior medial tibia plateau (MTP, p < 0.05) and medial femoral condyle (MFC, p < 0.05). A dMCL injury, a smaller differential medial–lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. MRI sensitivity was 62.5% and the specificity was 84.5%. Conclusion The presence on MRI of sMCL and/or dMCL lesions, bone oedema in the posterior MTP and MFC, and a smaller differential medial–lateral tibial slope than usual are highly associated with ramp lesions visible on MRI. Additionally, a dMCL injury, a flatter lateral tibial slope than usual, and the identification of a ramp lesion on MRI increases the likelihood of finding a ramp lesion at surgery. Knowledge of the risk factors and secondary injury signs associated with ramp lesions facilitate the diagnosis of a ramp lesion preoperatively and should raise surgeons’ suspicion of this important lesion. Level of evidence Diagnostic study, Level III.

Excessive anterior tibial translation in the contralateral uninjured limb is significantly associated with ramp lesion in anterior cruciate ligament injury

Purpose This study aimed to evaluate the excessive anterior tibial translation (ATT) and muscle strength of patients with ramp lesions. We hypothesised that the higher ATT, lower hamstring-to-quadriceps (HQ) ratio, and higher flexion peak torque influenced by semimembranosus would be associated with ramp lesions. Methods One hundred and twenty-one patients who underwent anterior cruciate ligament (ACL) reconstruction were retrospectively evaluated. Clinical evaluation included ATT of the contralateral uninjured limb measured using a KT-1000 arthrometer, the knee flexor and extensor muscle strength of the contralateral uninjured limb at 60°/s and 180°/s of an angular velocity measured using an isokinetic dynamometer, and HQ ratio at 60°/s and 180°/s during the preoperative state. Binary stepwise logistic regression analysis was performed to evaluate the risk factors of ramp lesions. Results Ramp lesions were found in 27 cases of ACL injuries (27/121, 22.3%). Male sex (odds ratio [OR], 2.913; 95% confidence interval [CI], 1.090–7.787; P = 0.033), longer time between injury to surgery (OR, 2.225; 95% CI, 1.074–4.608; P = 0.031), and higher ATT in the contralateral uninjured limb (OR, 1.502; 95% CI, 1.046–2.159; P = 0.028) were indicated as the independent risk factors of the presence of ramp lesion associated with an ACL injury. Conclusions Male sex, longer period from injury to surgery, and higher ATT in the contralateral uninjured limb were significantly associated with ramp lesion. These findings are advantageous for identifying patients with a greater risk of developing a ramp lesion with an ACL injury in the clinical setting. Level of evidence Level IV

Ramp lesion of the medial meniscus

Ramp lesion of the medial meniscus used to be completely disregarded in the past. Ramp lesion has been now put under the spotlight by orthopaedic and sport medicine surgeons and requires attention. It is closely associated with anterior cruciate ligament injury. Major risk factors include chronic laxity, lateral meniscal lesion, anterior cruciate ligament reconstruction revision, anterolateral ligament tear concomitant with anterior cruciate ligament injury, time from injury, pre-operative side-to-side laxity > 6 mm, age < 30 years old, male sex, etc. Radiologists attempt to create diagnostic criteria for ramp lesion using magnetic resonance imaging. However, the only definite method to diagnose ramp lesion is still arthroscopy. Various techniques exist, among which posteromedial approach is the most highly recommended. Various treatment options are available. The success rate of ramp repair is very high. Major complications are uncommon. Cite this article: EFORT Open Rev 2021;6:372-379. DOI: 10.1302/2058-5241.6.200126

Prevalence and Detection of Meniscal Ramp Lesions in Pediatric Anterior Cruciate Ligament–Deficient Knees

Background: Anterior cruciate ligament (ACL) tears represent 13% of knee injuries in children. Medial meniscal tears are commonly associated with ACL ruptures. Ramp lesions correspond to posterior meniscocapsular tears of the medial meniscus. Depending on the study, the prevalence of ramp lesions is inconsistent. Purpose: To describe the prevalence of ramp lesions in children and adolescents and to investigate the sensitivity of magnetic resonance imaging (MRI) for diagnosing such lesions. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: We analyzed videos from arthroscopic ACL reconstruction (ACLR) in children. During these procedures, we systematically looked for potential ramp lesions. To do so, an arthroscope was passed through the intercondylar notch to visualize the posteromedial compartment. A needle was introduced at the site of a posteromedial portal to unfold the meniscocapsular junction to reveal any hidden meniscal tear. Surgical procedures were performed by 2 senior surgeons. Videos were blindly analyzed by a third surgeon. Preoperative MRIs were screened by 2 blinded, independent senior radiologists to look specifically for ramp lesions. Results: Videos of 50 consecutive arthroscopic ACLRs concerning 32 boys and 18 girls were analyzed. Mean age at surgery was 14.2 years (range, 8.5-17.6 years). A total of 14 ramp lesions (28%) in 8 boys and 6 girls were identified. In addition, there were 22 tears of the meniscal body in 20 patients (40%). Arthroscopic and MRI findings did not correlate. Among 14 arthroscopically diagnosed ramp lesions, only 8 were detected on the MRI. Conversely, 12 patients had a ramp lesion detected on the MRI, which could not be confirmed intraoperatively. The sensitivity of MRI was 57% and the positive predictive value was 40%. Conclusion: A meniscal ramp lesion was present in 14 of 50 children (28%) undergoing ACLR. MRI has a low sensitivity for diagnosis of ramp lesions in children. Careful exploration of the posteromedial compartment is strongly recommended. Overlooking such lesions during ACLR may contribute to ongoing instability and higher re-rupture rates in these young patients.